What is Cystinosis?
Cystinosis is an ultra rare metabolic disease characterise by the accumulation of amino acid, cystine, in organs and tissues, leading to severe organ dysfunction.
The amino acid, cystine, is an amino acid stored in the lysosome of cells. In Cystinosis, the transporter for cystine is dysfunctional, causing a build up of cystine in the cells which then crystallise. These crystals quickly create toxic levels of cystine in the body, causing cellular dysfunction and even cellular death. Soft tissue and all organs are directly affected by this crystallisation, including the kidneys, eyes, liver, muscles, and central nervous system.
Symptoms – There are three clinical forms of cystinosis:
- Infantile (nephropathic) cystinosis
- late-onset cystinosis;
- benign cystinosis
Download Booklet: Cystinosis-Booklet.pdf
The information presented above is intended for general education purposes only, and should not be construed as advising or diagnosis or treatment of this or any other medical condition.
1. Infantile Cystinosis
This is the most severe and the most common type of cystinosis. Children with nephropathic cystinosis appear normal at birth, but by 9-10 months of age have symptoms that include:
- Excessive thirst and urination
- Failure to thrive (Under-weight & under-sized)
- Nausea and Vomiting
- Photophobia (eyes sensitive to light)
- Rickets (due to low levels of phosphate and Vitamin D)
- Episodes of dehydration
2. Late-onset Nephropathic
This is not usally diagnosed before the age of 12 years and the disease progresses slowly.
Cystine crystals are present in the cornea and conjunctiva of the eye and in the bone marrow.
3. Adult Cystinosis (Benign or Non- Nephropathic)
Cystinsosis begins in adulthood and does not affect the kidneys in any way.
Cystine accumulate in the cornea and conjunctiva of the eye and photophobia is present.
Effects of Cystinosis
Over a period of years, the cystine damages various organs including the kidneys, liver, muscles, white blood cells, eyes and central nervous system. The cystine crystallizes in cells throughout the body, slowly destroying the organs. The earliest abnormalities are seen in the kidney. Cystinosis is a common cause of the Fanconi syndrome, a renal tubular disease. By about one year of age, patients have very large volumes of urine and lose large amounts of salt and other minerals in their urine.
Without specific treatment, these children progress to end-stage renal failure by an average age of nine years. In the past, this meant death. Now these patients can receive renal dialysis or renal transplantation. However, even with successful renal transplantation, these children go on to develop abnormalities in other organs.
Fortunately, the drug cysteamine slows the progression of cystinosis by removing the cystine from the cells. In order for the drug treatment to be effective, it must be taken every six hours. Although this has led to a much better future for these children, cysteamine is not a cure.